FM radio TA2003 Configuration confusion

[Masood_786]

Hi All,

I have soldered the circuit for Tv Tuner demodulator (FM) as explained in web site
_-= Uzzors2k =-_ Project Site
The diagram i have attached as "Tv Tuner Radio" but mine is not working, i doubt author has forgotten the input at pin 15 of TA2003 IC (may be author is correct as it is FM RF output which is what input to pin1 from output) but another web site
**broken link removed**
shows tank circuit connection to Pin15 (but tank circuit for Pin13 and and
Pin 15 is different so at any time of tuning they would have different oscillating frequencies, as different coils and capacitor across)
The figure is attached as "FM_Am_Radio".
Please help me on this i am really frustrated with it, also you can see that in both approaches for Ceramic filter and Discriminator connections both authors have used different approaches, one used resistor with filter but other didn't, one used capacitor with discriminator but other used resistor. I also connected circuit for FM radio(not tuner) without connecting anything at pin15 but it's not working, i don't know how both authors are successful in their approach, i mean any one should be correct.

 

[VSMVDD]

one of the authors designs is far far more complex that the others

i feel its up to needs

if you dont need it dont design a circuit that is up to the job you dont need

you must have a fault or problem

ive been very many times 20 or more full times over a single circuit to only find a small shard of solder
blocks rf

or a bad cap has been damaged on install etc etc

maybe you need to do more tests before condem your fine work

 

[Takeshi-san]

Keep it simple, use Toshiba datasheet TA2003 datasheet pdf datenblatt - Toshiba Semiconductor - AM/FM RADIO IC ::: ALLDATASHEET :::

page 7. You will find all your answers

 

[Masood_786]

Thank guys but i am still confused why one needs to connect tank circuit to Pin(15) which is FM RF output even on data sheet it is shown, also L(inductor) for both inputs can't be perfectly same. Why can't we distribute a single tank circuit out to pin13 and pin 15 and why separate tank circuits are required.

 

[Takeshi-san]

It's obvious - in the second circuit TA2003 is IF+FM detector, but first using whole IC. You should read datasheet again and more carefully. That IC described very well